Here I will present a Power Amplifier 500W with Speaker Protection Output power up to 500 Watts in which, there is the protection system in the speaker output. And a buffer amplifier circuit also mix between IC Op-Amp 4558 with a transistor.
Circuit Diagram Power Amplifier 500W with Speaker Protection
This power amplifier circuit using transistor 2N5401/2N551 and the Op-Amp IC JRC4558. And for transistor driver using transistor; 2x MJE340-MJE350, A1837-B1186-A1930, C4794-D1763-C5171.
And last main booster amplifier is needed 14x SA1943 - SC5200. The booster transistor you must parallel , connect base 2SC and 2SA . See booster transistor amplifier circuit. And below image for PCB Layout design.
PCB Layout design